Impact of the preservation media on ex vivo bone samples for full field mechanical testing.

The preservation method to store bone tissue for posterior analysis is a widespread practice. However, the method's potential influence on the material's mechanical properties is often overlooked during single-point experimentation. Saline and formaldehyde solutions are the most common among the employed preservation media. A full field analysis of the mice femoral bone deformation using non-destructive optical techniques is conducted to assess the influence of the storage media on the viscoelastic properties of the tissue. Three different groups are subjected to a standard three-point bending test. The first group is the control, with fresh post-mortem samples. The second and third groups used saline and formaldehyde solutions, respectively. During the mechanical test, the bone's surface and internal deformation are monitored simultaneously using digital holographic interferometry and Fourier-domain optical coherence tomography. A mechanical comparison among the three groups is presented. The results show that after 48 h of immersion in saline solution, the mice bones keep their viscoelastic behavior similar to fresh bones. Meanwhile, 48 h in formaldehyde modifies the response and affects the marrow structure. The high sensitivity of the optical phase also makes it possible to observe changes in the anisotropy of the samples. As a comparison, Raman spectroscopy analyzes the three bone groups to prove that the preservation media does not affect a single-point inspection.

Trap-assisted enhancement of the responsivity in asymmetric planar GaN-based nanodiodes at low temperature.

The microwave detection capability of GaN-based asymmetric planar nanodiodes (so-called Self-Switching Diode, SSD, due to its non-linearity) has been characterized in a wide temperature range, from 70 K up to 300 K. At low temperature, microwave measurements reveal an enhancement of the responsivity at frequencies below 1 GHz, which, together with a pronounced hysteresis in the DC curves, indicate a significant influence of the surface states. This leads to a significant variability and non-repeatability which needs to be reduced since it degrades the accuracy of the detection. For this sake, the RF characterization was repeated after applying a positive/negative voltage able to fill/empty the surface states in order to have a well-established preconditioned state. As a consequence of the positive pre-soak bias, a significant enhancement of the measured responsivity, with a × 10 increase at low temperature. The RF detection measurements after such preconditioning contains a time dependence induced by the slow discharge mechanism of the traps, so that the improved responsivity remains even after 100s of seconds. On the other hand, a negative voltage pre-soak benefits the discharge process, thus suppressing the low frequency dispersion and the important variability of the detection without the pre-conditioning step. We also show that the relation between the voltage and current responsivities in each case allows to explain the impact of the surface charges in terms of the device impedance.

Concurrent optical inspection to boost characterization of plastic cortical bone under mechanical deformation.

The simultaneous surface and internal measurements from a chemically modified cortical bovine bone suffering a plastic range deformation are presented. Since the bone is an anisotropic structure, its mechanical response could be modified if its organic or inorganic phases change. The latter could result in high plastic deformations, where the interferometrical signal from an optical analysis is easily de-correlated. In this work, digital holography interferometry (DHI) and Fourier domain optical coherence tomography (FD-OCT) are used to analyze the plastic range deformation of the bone under compression. The simultaneous use of these two optical methods gives information even when one of them de-correlates. The surface results retrieved with DHI show the high anisotropy of the bone as a continuously increasing displacement field map. Meanwhile, the internal information obtained with FD-OCT records larger deformations at different depths. Due to the optical phase, it is possible to complement the measurements of these two methods during the plastic deformation.

Gabor's holography: seven decades influencing optics [Invited].

Dennis Gabor's seminal idea of a simple all-optical setup aimed at reconstructing the object wavefront stored on a photographic plate gave birth a little over seven decades ago to the field of holography. In 1971 Gabor obtained the Nobel Prize in Physics for this invention. Still, the road in the early days after his two first papers on the subject was one full of obstacles, so his scientific and engineering contemporaries put his idea to rest for more than 10 years, until the invention of the laser. This fact made his holographic concept take off to new and unsuspected applications. This invited review paper is a homage to Dennis Gabor's 50th anniversary of his Nobel Prize accolade. For this purpose, the review departs from the typical common route, i.e., those written following a timeline fashion, and instead is written with the intent to cover only a few of the holography applications in optics while scanning the electromagnetic spectrum. In doing this, the authors are aware that other invited papers for this special issue will tackle other subjects not dealt with in this review non-timeline paper.

Umbilical cord clamping and skin-to-skin contact in deliveries from women positive for SARS-CoV-2: a prospective observational study.

OBJECTIVE: To demonstrate that delayed cord clamping (DCC) is safe in mothers with confirmed SARS-CoV-2 infection. DESIGN, SETTING AND PARTICIPANTS: Prospective observational study involving epidemiological information from 403 pregnant women with SARS-CoV-2 between 1 March and 31 May 2020. Data were collected from 70 centres that participate in the Spanish Registry of COVID-19. METHODS: Patients' information was collected from their medical chart. MAIN OUTCOMES AND MEASURES: The rate of perinatal transmission of SARS-CoV-2 and development of the infection in neonates within 14 days postpartum. RESULTS: The early cord clamping (ECC) group consisted of 231 infants (57.3%) and the DCC group consisted of 172 infants (42.7%). Five positive newborns (1.7% of total tests performed) were identified with the nasopharyngeal PCR tests performed in the first 12 hours postpartum, two from the ECC group (1.7%) and three from the DCC group (3.6%). No significant differences between groups were found regarding neonatal tests for SARS-CoV-2. No confirmed cases of vertical transmission were detected. The percentage of mothers who made skin-to-skin contact within the first 24 hours after delivery was significantly higher in the DCC group (84.3% versus 45.9%). Breastfeeding in the immediate postpartum period was also significantly higher in the DCC group (77.3% versus 50.2%). CONCLUSIONS: The results of our study show no differences in perinatal outcomes when performing ECC or DCC, and skin-to-skin contact, or breastfeeding. TWEETABLE ABSTRACT: This study demonstrates that delayed cord clamping is safe in mothers with confirmed SARS-CoV-2 infection.

Flame analysis using a simple transmission digital holographic interferometer.

A digital holographic interferometer using a collimated beam in transmission mode to illuminate a flow coming from a diffusion flame is presented. The optical system proposes an indirect visualization of the flow to avoid saturation at the sensor. It can detect the intensity signal as a classical schlieren technique and the phase changes due to the presence of the flow. It is possible to retrieve a pseudo-3D flow's view and different gradient maps using the optical phase. According to the knife edge's position, these gradients could be observed in classical schlieren one at a time, but the proposed system could retrieve them all with a single image hologram. As proof of principle, a flame's flow is simultaneously observed with the optical system and a Z-type schlieren set up. A comparison of the visualized flows at different stages of the flame is presented and discussed. A temperature profile is obtained and validated with a thermocouple's point thermal measurements taking the resulting optical phase. Results from both optical techniques show a good agreement.

Fish swim water bulk displacement visualization with digital holographic interferometry.

A collimated transmission beam interferometer is used to measure the water motion provoked by the fish swimming through it. An indirect measurement of the fish motion impact in the water contained in a home-type aquarium is detected. Measurements of the whole aquarium are possible due to a large diameter collimated laser beam in the interferometer's object arm. This beam goes through the aquarium, and any perturbation inside it deflects the collimated beam. The interferometer detects a phase difference, i.e., the beam through the disturbed water undergoes different optical paths. This optical phase change was first demonstrated by means of a simple test using spherical steel marbles placed in a cuvette. For this, the small water movements for a single steel marble are detected with the acquired optical phase. Next, the aquarium optical phase results show water movements according to the fishes' size and swimming speed. It is worth mentioning that no additives were added to the aquarium's fresh water during the tests, so the water was crystal clear.

Trap-related frequency dispersion of zero-bias microwave responsivity at low temperature in GaN-based self-switching diodes.

The zero-bias microwave detection capability of self-switching diodes (SSDs) based on AlGaN/GaN is analyzed in a wide temperature range, from 10 K to 300 K. The measured responsivity shows an anomalous enhancement at low temperature, while the detected voltage exhibits a roll-off in frequency, which can be attributed to the presence of surface and bulk traps. To gain a deep insight into this behavior, a systematic DC and AC characterization of the diodes has been carried out in the mentioned temperature range. DC results confirm the existence of traps and AC measurements allow us to identify their properties. In particular, impedance studies enable to distinguish two types of traps: at the lateral surfaces of the channel, with a wide spread of relaxation times, and in the bulk.

Utilisation/upgrading of orange peel waste from a biological biorefinery perspective.

Orange peel waste (OPW) (peels, pulp and seeds) is an underutilised residue coming from the orange juice industry. Its classical applications are cattle feeding and composting, while they cannot ensure a total use of OPW, so landfilling is also common practice. On the other side, OPW is very rich in sugars, polysaccharides, essential oils and polyphenols, so there is a vast literature focused on the development and optimization of technologies and processes to several products from OPW. In this review, papers on OPW-based bioprocesses are visited, discovering a wide landscape that goes from the composting and biogas processes on detoxified OPW (deoiled) to bioprocesses to bioethanol, chemicals, flavours and polymers. All these processes are prone to integration within the 2nd-generation biorefinery framework.

Tethering QK peptide to enhance angiogenesis in elastin-like recombinamer (ELR) hydrogels.

The development of new capillary networks in engineered constructs is essential for their survival and their integration with the host tissue. It has recently been demonstrated that ELR-based hydrogels encoding different bioactivities are able to modulate their interaction with the host after injection or implantation, as indicated by an increase in cell adhesion and the ability to trigger vascularization processes. Accordingly, the aim of this study was to increase their angiogenic ability both in vitro and in vivo using a small VEGF mimetic peptide named QK, which was tethered chemically to ELR-based hydrogels containing cell-adhesion sequences in their backbone, such as REDV and RGD, as well as a proteolytic site (VGVAPG). In vitro studies were performed using a co-culture of endothelial and fibroblast cells encapsulated into the ELR-based hydrogels in order to determine cell proliferation after 21 days of culture, as well as the number of cell-cell interactions. It was found that although the presence of this peptide does not influence the morphological and rheological properties of these hydrogels, it has an effect on cell behaviour, inducing an increase in cell proliferation and the formation of endothelial cell clusters. In vivo studies demonstrate that the QK peptide enhances the formation of prominent functional capillaries at three weeks post-injection, as confirmed by H&E staining and CD31 immunohistochemistry. The newly formed functional microvasculature ensures perfusion and connection with surrounding tissues. These results show that ELR-QK hydrogels increase capillary network formation and are therefore attractive candidates for application in tissue regeneration, for example for the treatment of cardiovascular diseases such as myocardial infarction or ischemia.

Transmission out-of-plane interferometer to study thermal distributions in liquids.

An optical setup that does not need in-line alignment of the object illumination and camera sensor, or requires a reflection mirror after the sample, is introduced to observe the optical phase in a heating liquid. This system uses an out-of-plane transmission digital holographic interferometer that uniformly adds speckle to the image holograms by means of a neutral phase screen. The way in which the liquid is illuminated allows having a variable magnification of the observed area of the sample. As a proof of principle, a thermal time-dependent distribution experiment is presented, whose resulting optical phase readily depicts the temperature-time-varying distribution in the liquid.

Production of D-lactic acid by Lactobacillus delbrueckii ssp. delbrueckii from orange peel waste: techno-economical assessment of nitrogen sources.

In this study, the effect of several organic nitrogen sources (namely peptone, meat extract-ME, yeast extract-YE, and corn steep liquor-CSL) on D-lactic acid production by Lactobacillus delbrueckii ssp. delbrueckii has been studied. While lactic acid bacteria (LAB) are well-known for their complex nutritional requirements, organic nitrogen source-related cost can be as high as 38% of total operational costs (OPEX), being its nature and concentration critical factors in the growth and productivity of the selected strain. Corn steep liquor (CSL) has been chosen for its adequacy, on the grounds of the D-lactic acid yield, productivity, and its cost per kilogram of product. Finally, orange peel waste hydrolysate supplemented with 37 g/l CSL has been employed for D-lactic acid production, reaching a final yield of 88% and a productivity of 2.35 g/l h. CSL cost has been estimated at 90.78$/ton of D-lactate.

A multicentre study on epidemiology and prevention of needle stick injuries among students of nursing schools.

INTRODUCTION: Among the health professions with a long period of training, the students of the Nursing Bachelor's Degree are the most exposed to biological risk resulting from accidents, in particular with needles and cutting edges. The aim of the study was to estimate the frequency and the circumstances for the occurrence of needle stick injuries, as a knowledge base for targeted prevention interventions. METHODS: The study was carried out between May and July 2017 in 11 Universities in Italy and 1 in Albania (associated with the "Tor Vergata" University of Rome). An anonymous semi-structured questionnaire was proposed to 1st (second semester), 2nd and 3rd year students of Nursing Bachelor's Degree. RESULTS: A total of 2742 questionnaires were collected. The average age of participants was 22.9 years (median 22, range 19-60 years), 73% of whom were females. A total of 381 injuries were reported. Three hundred and sixteen students (11.8%) underwent at least 1 injury (12.7% among females, 9.7% among males); 41 students declared two or more injuries; four students did not report the number of injuries occurred. The first injury occurred, as an average, 17 days after the start of the internship (median 15 days) and, in 25% of the cases, during the first 9 days. The highest percentage of accidents occurred during the first internship (25.3% of the total) and decreased with the progress of the training path. The injuries occurred in 38% of cases during drug preparation, 24% when disposing of sharp devices, 15% while re-capping needles, 13% during blood sampling and 10% in other circumstances. In 51.2% of cases, the needle was not sterile. Among the nursing students who suffered a needle stick injury, 58.1% declared that they had performed the post-exposure prophylaxis. 96% of students stated to be vaccinated against Hepatitis B virus. Amongst the students who had their serological status checked (74%), 18% stated the antibody titre was not protective. 49.8% of students answered to have been trained in advance on the correct procedures to avoid needle stick and cutting edges injuries in each clinical ward attended, 41.2% referred that this occurred only in some wards and 10% in no ward at all. CONCLUSION: The results of this study show a high percentage of needle stick injuries in students of the Nursing Bachelor's Degree. Therefore, there is a need for careful reflection on the most effective methods of targeted training acquisition of knowledge, skills and behavioural models useful for the exercise of the profession.

Knowledge, experiences, and attitudes toward Mantoux test among medical and health professional students in Italy: a cross-sectional study.

BACKGROUND: The World Health Organization's Action Framework for tuberculosis elimination in low-tuberculosis incidence countries includes the screening for active and latent tuberculosis in selected high-risk groups, including health care workers. In this context, medical and health profession students, exposed to nosocomial tuberculosis transmission during training and clinical rotations, are target populations for tuberculosis screening. No updated data are available on tuberculosis screening practice and knowledge of medical and health profession students in Italy. METHODS: Within the activities Italian Study Group on Hospital Hygiene of the Italian Society of Hygiene, Preventive Medicine and Public Health, we carried out a multicentre cross-sectional study to assess knowledge, attitude and practices on tuberculosis prevention and control among Medical, Dentistry, Nursing and other health professions' students. Students were enrolled in the study on a voluntary basis and were administered a previously piloted structured questionnaire. Logistic regression models were applied to explore knowledge on tuberculosis prevention by selected socio-demographic variables and University-based tuberculosis prevention practice. RESULTS: Students of seventeen Universities across Italy participated in the study, and 58.2% of them received compulsory tuberculin skin test either at enrollment or while attending clinical practice. A total of 5,209 students filled the questionnaire. 37.7% were medicine and dentistry students (Group 1), 44.9% were nursing students (Group 2) and 17.4% were other health professions' students (Group 3). Age and gender had different distributions by groups, as well as knowledge and practice on tuberculin skin test. 84.4% of the study population (95% CI = 83.3-85.3) was aware of the existence of the tuberculin skin test, 74.4% (95% CI = 73.2-75.6) knew what is the first-level screening test for latent tuberculosis and only 22.5% (95% CI = 21.4-23.6) knew how to proceed after a positive tuberculin skin test result. Overall, knowledge on tuberculosis prevention was higher in Group 2 and lower Group 3, as compared to Group 1. CONCLUSION: In Italy, the knowledge on tuberculosis screening among University students is generally good. To reduce some of the criticalities found among the different study courses, it would be appropriate to harmonize both the regulations on tuberculosis screening practices for admission to University courses, and the educational activities on the topic of tuberculosis, to be extended to all workers involved in health care setting.

B cell phenotypes in patients with rheumatoid arthritis relapsing after rituximab: expression of B cell-activating factor-binding receptors on B cell subsets.

Serum levels of B cell-activating factor (BAFF) rise following rituximab (RTX) therapy in patients with rheumatoid arthritis (RA). Initiation of naive B cell return to the periphery and autoreactive B cell expansion leading to relapse after RTX may therefore be linked to interactions between BAFF and BAFF-binding receptors (BBR). Relationships between serum BAFF and BBR expression [(BAFFR, calcium signal modulating cyclophilic ligand interactor (TACI) and B cell maturation antigen (BCMA)] were determined on B cell subsets, defined using immunoglobulin (Ig)D/CD38. Twenty pre-RTX and 18 RA patients relapsing after B cell depletion were included. Results were analysed with respect to timing of relapse up to 7 months after peripheral B cell return (≥ 5 B cells/µl) and to serum BAFF levels. After B cell return, B cell populations from relapsing patients had significantly lower BAFFR+ expression compared to HC and pre-RTX patients. The percentage of BAFFR+ B cells increased with time after B cell return and was correlated inversely with serum BAFF levels. BAFFR expression remained reduced. The percentage of TACI+ memory B cells were lower in RA patients after RTX compared with healthy controls (HC). BCMA expression (% and expression) did not differ between patients and HC. Relapse following B cell return appeared largely independent of the percentage of BAFFR+ or percentage of BCMA+ B cells or serum BAFF levels. The lower percentage of TACI+ memory B cells may reduce inhibitory signalling for B cell differentiation. In patients relapsing at longer periods after B cell return, recovery of the B cell pool was more complete, suggesting that selection or expansion of autoreactive B cells may be needed to precipitate relapse.

Surface structural damage study in cortical bone due to medical drilling.

A bone's fracture could be produced by an excessive, repetitive, or sudden load. A regular medical practice to heal it is to fix it in two possible ways: external immobilization, using a ferule, or an internal fixation, using a prosthetic device commonly attached to the bone by means of surgical screws. The bone's volume loss due to this drilling modifies its structure either in the presence or absence of a fracture. To observe the bone's surface behavior caused by the drilling effects, a digital holographic interferometer is used to analyze the displacement surface's variations in nonfractured post-mortem porcine femoral bones. Several nondrilled post-mortem bones are compressed and compared to a set of post-mortem bones with a different number of cortical drillings. During each compression test, a series of digital interferometric holograms were recorded using a high-speed CMOS camera. The results are presented as pseudo 3D mesh displacement maps for comparisons in the physiological range of load (30 and 50 lbs) and beyond (100, 200, and 400 lbs). The high resolution of the optical phase gives a better understanding about the bone's microstructural modifications. Finally, a relationship between compression load and bone volume loss due to the drilling was observed. The results prove that digital holographic interferometry is a viable technique to study the conditions that avoid the surgical screw from loosening in medical procedures of this kind.

Phonon black-body radiation limit for heat dissipation in electronics.

Thermal dissipation at the active region of electronic devices is a fundamental process of considerable importance. Inadequate heat dissipation can lead to prohibitively large temperature rises that degrade performance, and intensive efforts are under way to mitigate this self-heating. At room temperature, thermal resistance is due to scattering, often by defects and interfaces in the active region, that impedes the transport of phonons. Here, we demonstrate that heat dissipation in widely used cryogenic electronic devices instead occurs by phonon black-body radiation with the complete absence of scattering, leading to large self-heating at cryogenic temperatures and setting a key limit on the noise floor. Our result has important implications for the many fields that require ultralow-noise electronic devices.

Report on the second International Consensus on ANA Pattern (ICAP) workshop in Dresden 2015.

The second meeting for the International Consensus on Antinuclear antibody (ANA) Pattern (ICAP) was held on 22 September 2015, one day prior to the opening of the 12th Dresden Symposium on Autoantibodies in Dresden, Germany. The ultimate goal of ICAP is to promote harmonization and understanding of autoantibody nomenclature, and thereby optimizing ANA usage in patient care. The newly developed ICAP website www.ANApatterns.org was introduced to the more than 50 participants. This was followed by several presentations and discussions focusing on key issues including the two-tier classification of ANA patterns into competent-level versus expert-level, the consideration of how to report composite versus mixed ANA patterns, and the necessity for developing a consensus on how ANA results should be reported. The need to establish on-line training modules to help users gain competency in identifying ANA patterns was discussed as a future addition to the website. To advance the ICAP goal of promoting wider international participation, it was agreed that there should be a consolidated plan to translate consensus documents into other languages by recruiting help from members of the respective communities.

The radiologist's role in child abuse: imaging protocol and differential diagnosis. / El papel del radiólogo ante el niño maltratado. Protocolo de imagen y diagnóstico diferencial.

Child abuse or nonaccidental trauma is a major problem worldwide; in Spain, there are about 12,000 victims per year. The detection of specific lesions or findings that are incongruent with the reported mechanism of trauma mean that radiologists are often the physician responsible for sounding the alarm in cases of abuse. The triad consisting of subdural hematoma, metaphyseal fracture, and posterior rib fractures is very characteristic of the battered child syndrome. The finding of acute and chronic lesions in the same patient is highly specific for nonaccidental trauma. Fractures of long bones in patients who have yet begun to walk should also alert to possible child abuse. Lesions that are highly specific for abuse, such as classic metaphyseal fractures or posterior rib fractures, can be difficult to demonstrate radiographically and are usually clinically occult. The American College of Radiology (ACR) protocols recommend obtaining three separate X-rays of each upper and lower limb. It is important to use X-ray systems that give high resolution images with low kilovoltage (50-70 kvp) and appropriate milliamperage. A skeletal survey consisting of a series of images collimated to each body region is recommended for all children under the age of two years in whom abuse is suspected. A follow-up skeletal survey about two weeks after the initial survey is useful for detecting new fractures and for assessing the consolidation of others, which helps in dating the lesions. Head injuries are the leading cause of death in abused children. Although computed tomography is the first neuroimaging technique in nonaccidental trauma, magnetic resonance imaging of the head can better characterize the lesions seen on computed tomography and can help to estimate the age of the lesions.

Effect of rituximab on B cell phenotype and serum B cell-activating factor levels in patients with thrombotic thrombocytopenic purpura.

Autoantibodies inhibiting the activity of the metalloproteinase, ADAMTS13 (a disintegrin and metalloproteinase with a thrombospondin type 1 motif, member 13), underlie the pathogenesis of thrombotic thrombocytopenic purpura (TTP). Rituximab (RTX) combined with plasma-exchange (PEX) is an effective treatment in TTP. Patients can remain in remission for extended periods following PEX/RTX, and this is associated with continuing reduction in antibodies to ADAMTS13. Factors controlling B cell differentiation to autoantibody production, including stimulation through the B cell receptor and interactions with the B cell-activating factor (BAFF), may thus impact length of remission. In this cross-sectional study, we measured naive and memory B cell phenotypes [using CD19/immunoglobulin (Ig)D/CD27] following PEX/RTX treatment in TTP patients at B cell return (n=6) and in 12 patients in remission 10-68 months post-RTX. We also investigated relationships among serum BAFF, soluble CD23 (sCD23(-) a surrogate measure of acquiring B memory (CD27(+) ) phenotype) and BAFF receptor (BAFF-R) expression. At B cell return after PEX/RTX, naive B cells predominated and BAFF-R expression was reduced compared to healthy controls (P<0.001). In the remission group, despite numbers of CD19(+) B cells within normal limits in most patients, the percentage and absolute numbers of pre-switch and memory B cells remained low, with sCD23 levels at the lower end of the normal range. BAFF levels were correlated inversely with BAFF-R expression and time after therapy. In conclusion, the long-term effects of RTX therapy in patients with TTP included slow regeneration of memory B cell subsets and persistently reduced BAFF-R expression across all B cell subpopulations. This may reflect the delay in selection and differentiation of potentially autoreactive (ADAMTS13-specific) B cells, resulting in relatively long periods of low disease activity after therapy.